Propeller



March 16, 1965 P. Dl CESARE 3,173,492

PROPELLER Filed oct. 15, 196s BYDJ# @d United States Patent ice 3,173,492 Patented Mar. 16, 1965 3,173,492 PRPELLER Pierino Di Cesare, 4612 Cottman Ave., Philadelphia 35, Pa. Filed Oct. 15, 1963, Ser. No. 316,315 4 Claims. (Cl. 170--172) This invention relates to propellers and, in particular, to a propeller having a novel hub construction.

In greater detail, this invention teaches a propeller hub construction having a shaped passageway wherein a dow of iuid from the turning propeller blades is used to increase the efficiency of the propeller.

This invention teaches a modification and improvement of my prior United States Patent No. 2,041,169, issued on May 19, 1936. In that patent, it was disclosed that a propeller hub having an internal passageway allowing a flow of fluid from the blades would increase the eiciency of the propeller by eliminating a partial vacuum formed behind the hub of the operating propeller. The vacuum created by the propeller hub moving through the iluid causes an unnecessary drag on the propeller and Vehicle. By means of a shaped fluid passageway through or within the hub of the propeller uid placed in motion by the blades is ejected into the area of partial vacuum thereby reducing or eliminating the drag.

It is the primary feature of this invention to utilize the moving ow of fluid as described above to assist in rotating the propeller and otherwise reduce the force required to rotate the propeller at the desired rate.

It is a further object of this invention to provide a novel hub construction wherein the shaped passageway receiving, guiding, and ejecting the duid from the propeller blades otherwise increases the efliciency of the propeller over the prior forms of the same size, weight, or

1 material.

Still another object of this invention is the provision of a propeller that is substantially vibration-free in operation. In the present embodiment, this objective is accomplished by scooping up and passing air through the hollow, central portion of the propeller hub thereby tending to balance and stabilize the entire construction.

It is still another object of this invention to teach various constructions of the propeller hub having the advantages described above.

These and other attended advantages will become more apparent from the description hereinbelow and from the attached drawings wherein:

FIG. 1 is a rear elevational view of one type of marine propeller embodying one form of the construction of this invention;

FIG. 2 is a side elevational View of the propeller shown in FIG. 1 with the rear face shown in FIG. 1 positioned at the top;

FIG. 3 is a perspective View of the propeller shown in FIG. 1 with the hub passageway shown in greater detail;

FIG. 4 is a side elevational view, partly in section, of the propeller shown in FIG. 1 incorporating a modification of the hub;

FIG. 5 is a rear elevational view of an air propeller incorporating one form of the construction of this invention;

FIG. 6 is a side elevational view of the propeller shown in FIG. 5.

FIGURE 7 is another view of the propeller shown in FIGURE 5. v

It should be understood, preliminarily, that the word propeller is used herein generically to designate any construction which propels a flow of fluid by rotation. This invention linds application in ordinary cooling fans, in large airplane propellers and in many other forms designed for varying uses.

Referring now to FIG. 1 of the drawing, one specific form of propeller or fan according to the teaching of this invention is designated generally by the numeral 2. This form of propeller or fan is generally designed for marine use or as an air fan functioning, for example, as part of the cooling system of an automobile engine. The propeller 2 is shown having two radiating blades 10 and 12 joined to a raised hub 14 which has a centrally located bore 16 through which a drive shaft (not shown) fits. A key 18 is formed within the bore to lock the hub and the drive shaft together. Each of the blades 10, 12 is formed with a selected pitch or angle extending from the leading edges 10a, 12a to the rear edges 10b, 12b, respectively, according to the intended use. The blades can be of the stationary pitch type or mounted on the hub to be adjustable according to the operating conditions such as in the case of airplane propellers. Similarly, the propeller can be equipped with three or more blades and the width and length of each blade can vary according to the intended use. This invention is centered in the provision of a novel hub construction which can accommodate the above modification.

The hub 14, as shown in FIG. 1, joins both blades 10 and 12 by means of a pair of graduated sloping shoulders 15 and 17, respectively, on the rear face shown and the hub is substantially flat and not raised from the blades on the opposing front face, as indicated in FIG. 2. The shoulders 15, 17 provide structural strength between the hub and the blades and are shown in this figure as formed in one piece with the blades. A cylindrical collar 20, shown in broken lines, extends from one side of the hub to the other around the bore 16 thereby reinforcing the hub and surrounding the drive shaft.

Extending completely through the hub, as illustrated in FIG. 1 by dotted lines, is a passageway 22 or channel through which fluid, either liquid or gas, is driven by the rotating propeller blades. When the propeller rotates in the direction indicated by the arrows in FIG. 1, fluid is displaced or dispelled into the passageway 22 through the opening 24 by the leading edge 10a and the following curved surface of blade 10 until the fluid emerges at the opposite end of the passageway at opening 26. Similar- 1y, blade 12 causes fluid to pass through the passageway 22 in the opposite direction. The streams of huid do no-t directly oppose each other because the ow from blade 10 tends to pass above the collar 20 within passageway 22 while the llow from blade 12 passes beneath collar 20 50 as shown in FIG. 1. This flow from the rotating blades into the area around the driving shaft at the rear of the propeller substantially reduces a partial vacuum created just behind the hub before the rear face as shown and thereby reduces drag caused by air eddies.

To produce greater efficiencies in operation and to provide a thrust which assists in rotating the propeller, the

hub passageway is constructed according to the principle of the following design. The top side wall 32, as shown in FIG. 1, of the passageway 22 consists of a substantially straight portion 32a extending at an angle of approximately 45 degrees to the longitudinal axis of the propeller and a curved, angled or extended portion 32b which forms a uid deiiecting surface. Similarly, in the wall 33 at the bottom of passageway 22, a substantially straight portion 33a joins an extended deecting surface 33h. The deliecting surfaces 32b and 3319 are positioned beyond the centerline of rotation of their respective walls 32, 33, the centerline being indicated in FIG. l by the vertical dot and dash line. The lluid thrown from the moving blades first passes freely into the openings 24, 2 6 of the passageway 22 within the hub and along the straight portions 32a, 33a of the side walls until it is displaced partially laterally by the defiecting surfaces 32b, 33b. As a result of this deflection, reaction forces are created or caused against surfaces 32h, 33h in a direction substantially perpendicular to said surfaces and, because the two surfaces 32b, 33h are beyond the centerline of rotation of the propeller, the forces, or components thereof, act in the direction of rotation of the propeller. In this way, the deflecting of the liquid passing through the hub assists in rotating the propeller. It should be understood that the shape, size, and location of the defiecting surfaces can vary according to the design of the propeller hub and also according to the operating conditions of the propeller. The deflecting surfaces would be constructed to produce the greatest forward drive commensurate with other objectives.

In FIG. 2, the propeller of FIG. 1 is shown from the side. It is seen that the blades 10, 12 are provided with a definite pitch and passageway openings 24, 26 provide for the free liow of uid through the propeller hub. The hub bore 16, the key 18 and the encircling cylindrical wall 20 are shown in dotted lines.

A perspective view of the propeller of FIG. l, as seen from the rear, is shown in FIG. 3. The passageway 22, dividing around structural member 20, is shown in greater detail.

Referring now to FIG. 4, a modification of the hub shown in FIG. l is disclosed. In place of the collar 20, the hub 50, shown in sectional view, is equipped with a front boss 51 and a rear boss 52 which support the propeller on the drive shaft 59. A pair of keys S4, 56 lock each boss to the shaft. Upon the front threads 58 of shaft 59, a nut 60 with cotter pin 62 is mounted. The reinforced bosses 51, 52 are sufficiently strong to support the hub proper and the blades. In this figure, the blade 63 shown in side elevation, has a leading edge 64 and a trailing edge 66 and rotates out of the plane of the paper. The passageway opening 65 receives the fluid from blade 63 and the uid passes around the exposed shaft 59 and out the opposing opening.

In FIGS. 5 through 7, a specific form of airplane pro peller embodying the improvements of this invention are shown. The propeller blades 70, 72 are of typical size and `shape and can be stationary or variable pitch. As seen in FIG. 5, the rear of the propeller has a raised hub 74 and two sloping shoulders 76 and 78 joining the two blades 70, 72, respectively. The hub is provided with a bore 75 for the purpose described above. The hub 74 has a passageway 80, as indicated by the broken lines, which is shaped to provide internal deflecting surfaces 82, 84. As explained in connection with the marine propeller of FIG. l, air displaced by blade 72 passes through the passageway 80 until it is deflected laterally by the extending surface 82 which is positioned beyond the centerline of rotation, thereby imparting a force on the surface 82 and assisting in rotating the propeller. Similarly, liuid deflected by blade 70 proceeds in the opposite direction through the passageway 80 and is defiected from surface 84 thereby urging said surface and the huby in the clockwise direction.

In FIGS. 6 and 7, the hub 74 and the bore 75 and opening 8G are also shown. The hub shoulders 76 and 78 are shown sloping to the propeller blades 70, 72.

While the construction of the huh has been described hereinbefore as integral with that of the propeller blades, it should be understood that the hub can be formed in two pieces, each half formed as part of a separate blade and then the blades and hub joined by welding or the like. Another satisfactory method of constructing the propeller of this invention is to construct a one piece hub and then join the hub to separate blades. In either case, the welding and subsequent preparation steps produce a smooth surface propeller.

By means of the construction described herein and any equivalent structure, the efficiency of an otherwise ordinary. propeller or fan used either in air or in a liquid medium is improved by the ow through hub thereby reducing certain propeller drag. In addition, the shaped hub construction of this invention causes the flow of iiuid to assist in rotating the propeller. It will be readily understood that the shape of the hub passageway can vary without departing from this invention and the use of different materials will likely call for some variance in the design.

Although this invention has been described with reference to specific forms and embodiments thereof, it will be apparent to those skilled in the art that various changes other than those referred to above may be made in the form of the apparatus, that equivalent elements may be substituted for those illustrated in the drawings, that parts may be reversed, and that certain features of the invention may be used to advantage independently of the use of other features, all such changes being within the spirit and scope of the invention as defined in the appended claims.

Having described my invention, I claim:

1. A propeller having a plurality of blades,

a hub joining said blades and arranged for mounting on a drive shaft, said hub having j a passageway formed therethrough for allowing a flow of fluid from one blade across the hub, said passageway positioned at approximately 45 degrees to the longitudinal axis of the propeller,

a deflecting surface positioned in relation to the passageway so as to be partially within the flow of fluid whereby the tiow of uid urges the de ecting surface in the direction of rotation of the propeller.

2. In a propeller having at least two blades, a hub portion joining said blades, said hub portion having a passageway for allowing a ow of fiuid from at least one blade therethrough, said passageway defining a first surface extending substantially at an oblique angle to the longitudinal axis of the propeller, said axis being defined by two co-linear blades, and

a second surface positioned so as to partially de ect the flow of fiuid passing through the passageway, said surface being so located in relation to the axis of rotation of said propeller as to create a drive component of force on said propeller operating in the direction of rotation of the propeller.

3. The propeller as defined in claim 2 wherein said passageway is positioned at approximately 45 to the longitudinal axis of the propeller, said axis being defined by two co-linear blades.

4. In a propeller having two blades, a hub portion joind ing said blades, said hub portion having a passageway for allowing a fiow of fluid from both blades therethrough, I means dividing the passageway into two channels', each channel receiving the fluid flow from a sepate blade, each channel defined by a first surface extending at an oblique angle to the longitudinal axis of the propeller, said axis being defined by the co-linear blades, and a second deiiecting surface positioned at an angle to said first surface so as to partially deflect the fiow of fluid passing through said channel, said surface being located in relation to the direction of fluid iiow and the axis of rotation of the propeller so as to create a drive component of force on said propeller operating in the direction of rotation of said propeller.

References Cited by the Examiner UNITED STATES PATENTS 2,041,169 5/36 Di Cesare 170-172 2,058,122 10/36 Assala 170-172 JULIUS E. WEST, Primary Examiner. 

1. A PROPELLER HAVING A PLURALITY OF BLADES, A HUB JOINING SAID BLADES AND ARRANGED FOR MOUNTING ON A DRIVE SHAFT, SAID HUB HAVING A PASSAGEWAY FORMED THERETHROUGH FOR ALLOWING A FLOW OF FLUID FROM ONE BLADE ACROSS THE HUB, SAID PASSAGEWAY POSITIONED AT APPROXIMATELY 45 